<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>

</head>

<body>
    <button onclick="alert('行内js')">行内js</button>


    <!--内部js-->
    <script>
        alert('你好,js~')
    </script>
    <!--通过src引入外部js-->
    <script src="02.my.js"></script>
</body>

</html>